This invention relates to a joint for connecting pipes and more particularly to a joint which is especially adapted for connecting plastic pipe sections to each other in a minimum of time to provide an effective sealed joint therebetween.
Heretofore in the art to which my invention relates, difficulties have been encountered in assemblying plastic pipe sections due to the fact that such pipe sections are usually assembled under adverse conditions in the field and also such pipes often convey abrasive materials which not only prevent rotation of the parts to be assembled relative to each other but also cut or damage the sealing gaskets or rings whereby an effective seal cannot be made. That is, plastic pipes are often employed in fly ash sluice lines, sour crude oil gathering lines and the like wherein fly ash, sand and other highly abrasive materials flow through the pipe. Also, in plastic lines which convey highly abrasive materials, such as fly ash, it is often necessary to rotate such lines periodically to prevent the bottom from eroding away due to friction resulting from movement of the fly ash against the bottom. With prior art joints it is very difficult and often impossible to rotate the pipe after assembly due to the fact that the O-ring surrounds and receives the adjacent component of the joint. In many cases the O-ring must be expanded as the adjacent component is forced therethrough whereby the O-ring is compressed. Difficulties have also been encountered with prior art joints for plastic pipe sections due to the fact that most joints for such pipe sections leave an annular space between the connected joint sections which brings about turbulence and cavitation which reduces the life of the joint. Such a joint is disclosed in the Carter U.S. Pat. No. 3,784,239. Also, some prior art pipe joints are provided with flanges which requires the installation of a plurality of bolts, thus greatly increasing the cost of the joint as well as increasing the time required to install the joint. Such a joint is disclosed in the Milette Pat. No. 3,197,242. Furthermore, prior art pipe joints which are not retained in place by a flange and bolt-like assembly often become loose after they have been in use for a period of time due to vibrations which cause the components of the joint to rotate relative to each other.